📊 Server Observability & Introspection

KacheDB provides self-describing runtime introspection compatible with modern Redis tooling, GUI clients (such as Redis Insight and TablePlus), and monitoring agents.

📋 Command Summary

Command	Syntax	Description
`INFO`	`INFO [section]`	Returns server, memory, traffic, keyspace, and vector statistics.
`HELLO`	`HELLO [protover [AUTH user pass] [SETNAME name]]`	Protocol handshake negotiating RESP2 or RESP3 and returning connection metadata.
`AUTH`	`AUTH [username] <password>`	Authenticates the connection when `requirepass` is configured.
`CLIENT`	`CLIENT <SETNAME \| GETNAME \| ID \| LIST>`	Inspects and configures client connection state.
`COMMAND`	`COMMAND [DOCS]`	Returns server capability descriptors for client auto-discovery.
`BGREWRITEAOF`	`BGREWRITEAOF`	Triggers asynchronous compaction and rewrite of the Append-Only File.
`QUIT`	`QUIT`	Gracefully closes the client connection.

🛠️ Detailed Command Reference & Examples

`INFO`

Outputs multi-section server metrics in standard Redis key-value format.

Syntax

INFO [server | memory | stats | keyspace | vector]

`kachedb-cli` Example

127.0.0.1:6379> INFO
# Server
kachedb_version:0.1.0
os:macos
arch_bits:64
process_id:48123
tcp_port:6379
uptime_in_seconds:1250

# Memory
used_memory:134217728
used_memory_human:128.00M
used_memory_peak:134217728
megaslabs_allocated:64
slab_slots_active:5120
fragmentation_ratio:1.00

# Stats
total_connections_received:128
total_commands_processed:150240
instantaneous_ops_per_sec:0
keyspace_hits:148000
keyspace_misses:2240

# Keyspace
db0:keys=5120,expires=450,avg_ttl=1820

# VectorEngine
active_indices:3
total_vectors:10240
vector_memory_bytes:655360
simd_kernel:auto

`HELLO`

Negotiates RESP wire protocol version with the server (supports version 2 and version 3).

Syntax

HELLO 3 [SETNAME client_name]

`kachedb-cli` Example

127.0.0.1:6379> HELLO 3 SETNAME my_worker
 1) "server"
 2) "kachedb"
 3) "version"
 4) "0.1.0"
 5) "proto"
 6) (integer) 3
 7) "id"
 8) (integer) 1
 9) "mode"
10) "standalone"
11) "role"
12) "master"
13) "modules"
14) (empty array)

`CLIENT`

Manages client connection names and identifiers.

Subcommands

CLIENT SETNAME <name>: Assigns a human-readable name to the current TCP connection.
CLIENT GETNAME: Retrieves the assigned name (or nil).
CLIENT ID: Returns the unique client connection ID.
CLIENT LIST: Returns connected client details.

`kachedb-cli` Example

127.0.0.1:6379> CLIENT SETNAME web_app_1
OK

127.0.0.1:6379> CLIENT GETNAME
"web_app_1"

127.0.0.1:6379> CLIENT ID
(integer) 1

`COMMAND` & `COMMAND DOCS`

Provides capability introspection so GUI tools and drivers can discover supported commands dynamically without crashing.

`kachedb-cli` Example

127.0.0.1:6379> COMMAND DOCS
OK

`AUTH`

Authenticates a client connection when password protection is enabled with requirepass.

Syntax

AUTH [username] <password>

`kachedb-cli` Example

127.0.0.1:6379> GET secret_key
(error) NOAUTH Authentication required.
127.0.0.1:6379> AUTH my_secure_password
OK
127.0.0.1:6379> GET secret_key
"confidential_data"

`BGREWRITEAOF`

Instructs the server to compact and rewrite the Append-Only File (kachedb.aof) to remove redundant commands and minimize disk space.

Syntax

BGREWRITEAOF

`kachedb-cli` Example

127.0.0.1:6379> BGREWRITEAOF
Background append only file rewriting started

KacheDB Documentation